Why exception from os.path.exists()?

[Marko Rauhamaa]

Paul Moore <p.f.moore at gmail.com>:
> On 1 June 2018 at 13:15, Barry Scott <barry at barrys-emacs.org> wrote:
>> Once you know that all of the string you provided is given to the
>> operating system it can then do whatever checks it sees fit to and
>> return a suitable result.
>
> As the programmer, I don't care. The Python interpreter should take
> care of that for me, and if I say "does file 'a\0b' exist?" I want an
> answer. And I don't see how anything other than "no it doesn't" is
> correct. Python allows strings with embedded \0 characters, so it's
> possible to express that question in Python - os.path.exists('a\0b').
> What can be expressed in terms of the low-level (C-based) operating
> system API shouldn't be relevant.

Interestingly, you get a False even for existing files if you don't have
permissions to access the file. Arguably, that answer is misleading, and
an exception would be justified. But since os.path.exists() returns a
False even in that situation, it definitely should return False for a
string containing a NUL character.


Marko